Most disputes over pledged money take place after donors have died and charities fear the heirs will fight over an estate. Either way, Hall says legal tangles with donors are risky endeavors on the part of the charities.

"The issue is they would be perceived as someone going after them when, through little or no fault of their own, they fell on hard times," Hall said. "That could make other donors hesitant to get into large gift agreements."

Kenneth Fitzgerald, a pro-bono attorney for the Dodges, said pursuing a default judgment on a couple who say they cannot afford an attorney is "mean-spirited and short sighted."

"I don't think they have a fiduciary duty to put one of their most generous donors into bankruptcy and unleash their lawyers and terrorize these people when they are destitute," Fitzgerald said. "It makes sense that they would want to collect a pledge if it's collectible. In this case, they know it's not."